I'd vote for that, too. Whatever comes out of that discussion on "coolness" on lkml ;o), I guess pv_ops is what will be the outcome. Inside or outside the linux kernel tree.

What I'd like to add is that I would prefer a better tagging of the kernel repo to identify subversion of the kernel that belong to a certain version of Xen, whatever kernel that might be. Fixes and improvements are happening so quickly that on the pure user's side the combination can make a difference, no matter how much effort you put in to keep it independent.

BR, Carsten.